| 摘要 |
PURPOSE:To attain good contrast and a high S/N with an optical card by forming a >=0.01mm gap between an optical recording part and a protection film. CONSTITUTION:An optical card 1 contains a substrate 2 which usually uses the acrylic resin, polycarbonate, nylon, polyolefin, etc. The thickness of the substrate 2 is set at about 0.1-1.0mm, and a recording layer 3 is provided on the substrate 2. While a protection film 4 is formed on an optical recording part by melt-sticking or adhering a film matter of polymer of a polyvinyl chloride group with about 0.1-1.0mm thickness. Furthermore a gap 5 is formed between the optical recording part and the film 4 with >=0.01mm length. In other words, a desired recess is formed to the film 4, and the film 4 is melt- stuck or adhered to the layer 3 or the substrate 2 through a projected part excepting said recess of the film 4. The layer 3 is shielded entirely from an outside system with the film 4 to prevent the deterioration of the layer 3. In such a way, both the contrast and the S/N are improved. |
